cardiac tamponade and electrical alternans

POSSIBLE EKG FINDINGS IN CARDIAC TAMPONADE:
--sinus tachycardia
--low voltage
--electrical alternans

ELECTRICAL ALTERNANS:

--beat to beat alternation in QRS appearance
--related to back & forth swinging motion of the heart in the pericardial fluid (thought this was a nice way of picturing it)


Reference(s): uptodate.com: cardiac tamponade; pendulum, EKG